The invention relates to a system and components thereof to control the covering of a core element with strands of reinforcing material by rotary braiding on tandem or adjacent machines.
As an operating unit, a rotary braiding machine suitable for being controlled according to the invention is now known, ad is described in the prior art.
The following United States Patents, now owned by the inventor's assignee, Karg Corporation, Tallmadge, Ohio U.S.A., disclose and claim various components of a rotary braiding machine suitable for control according to the invention: U.S. Pat. Nos. 3,756,117; 3,756,523: 3,756,533; and 3,757,904, each Sept./1973; and, 3,802,643, April/1974.
A machine suitable for being controlled according to the invention will have a rotating braiding mechanism and a revolving capstan drum for moving a flexible core element. The braiding mechanism and the capstan drum are powered by a variable speed motor.
The braiding mechanism includes a spool holder drive mechanism for actuating relative movement of a set of outer spools and a set of inner spools along circular paths in opposite directions. A material strand from each spool is let off toward the "work center" for braiding as to each other and around a moving flexible core element introduced coaxially of the braiding mechanism. The capstan includes a drive mechanism for actuating a revolving movement of a capstan drum. Multiple loops of a composite article, the core element with a covering of braided strands thereon, are wrapped around the drum in frictional engagement therewith.
In all known machine performed operations for covering a core element with a layer of braided strands, the "braid angle" or pitch of the braided strands will be established by the rate or speed of lineal progression during the circuar or wrapping movement of strands from the spools around the core element.
In the rotary braiding machines controlled according to the invention, the braid angle is a resultant of three factors: (1 ) outer diameter of the core element; (2) rate of lineal movement of the core element when passing through the "work center"; and, (3) rate of wrapping movement of the strands around the core element when in the "work center."
For any given dimensional factor (1), the greater the difference between the movement of factor (2) and the movement of factor (3), the lower or steeper the resultant braid angle. Conversely, for a given factor (1), a smaller difference between the movements of factors (2) and (3) will produce a product with a higher or flatter braid angle.
Control of tandem braiding machines according to the invention contemplates that each machine will have as a discrete operational component thereof an adjustable proportional control means to determine a specific braid angle for the strand covering on the core element. Each proportional control means will synchronize the revolving movement of the capstan drum (providing a lineal movement of a core element) and the circular movement of the sets of outer and inner spools (providing a wrapping movement of the strands). It is preferred that the power input to each proportional control means be from a single variable speed drive motor mounted on each machine frame.
The products which will be manufactured according to the invention are known, conventional, many and varied. The products may be plastic or rubber hose, cable, cord, line, or even rope. For this disclosure, the product shown is a very long length of rubber tubing reinforced by double-braided strands and intended for an end use, in suitable lengths and with suitable end fittings or couplings, in the transmission of hydraulic fluids under high pressure. Such a product is generically called "industrial hose."
Before now, there have been several types of techniques for continuous manufacture of industrial hose products disclosed in the prior art.
Commercial manufacturers of industrial hose products have long known of the company W & M Ostermann, Wuppertal-Barmen, Germany. The "Ostermann" equipment has included a horizontally operating machine with two rotating braiding mechanisms, "first pass" and "second pass," arranged symmetrically around a steel pole or rigid mandrel and having a caterpillar haul-off for the mandrel and multiple-braided product. U.S. Pat. No. 3,183,583, Ostermann, May/1965, discloses a horizontal machine used with two winding heads but otherwise structurally equivalent to the known "Ostermann" braiding machine.
A continuous process for the manufacture of reinforced hose using horizontally arranged tandem units for applying reinforcement "in the form of knitted, woven, braided or lapped textile yarns or the like between extruded elastomeric inner and outer layers" is disclosed in U.S. Pat. No. 3,586,558, Galloway et al, June/1971.
It has also been possible to use the "Karg" rotary braiding machines for the sequential manufacture of industrial hose products. An inner layer of braided strands is applied to a flexible core element during a "first pass" through a machine. The intermediate product is led from the capstan to suitable storage reels. After a suitable quantity of the intermediate product has been accumulated, the storage reels are positioned as supply reels and the outer braided strand layer is applied during a "second pass" through a machine.
It has now been found that an operable system to control the continuous process covering of a flexible core with multiple-braided strands of reinforcing material need not be complex, may be relatively inexpensive to install, operate and maintain, and will satisfactorily perform to produce large quantities of products with different braid angle and design specifications at a lowered direct labor cost with a reasonable capital investement.